A nut plate is a small plate to which a fastener nut is secured. It is used in aircraft on walls which do not permit the use of a threaded opening. The nut plate typically includes a pair of fastener openings spaced apart from each other at opposite ends of the nut plate. Fastener openings are drilled in a wall to which the nut plate is secured. The nut plate is positioned on the wall with its fastener openings in alignment with the fastener openings in the wall. Then rivets or other suitable fasteners are inserted through the aligned openings and used to secure the nut plate to the wall. A problem with this type of system is that there is wear at the rivets and fatigue in the wall where the rivets extend.
The nut carried by the nut plate includes a threaded opening for receiving a threaded end portion of a bolt. It is necessary that the wall include an opening for the bolt as the bolt is installed from the side of the wall opposite the nut. Accordingly, when a nut plate is used, it is necessary to form at least three openings in the wall for each nut, one to serve as a passageway for the bolt and at least two others to serve as fastener openings to receive fasteners that are used to secure the nut plate to the wall.
A principal object of the present invention is to provide a substitute for the nutplate which requires the formation of a single opening in the wall. Other nut plate substitutes are known, such as a flair nut and nuts on a carrier having a tubular mounting portion which is intended to friction fit within a single opening. A problem with such fasteners is that they rotate in the opening and do not stay in place and/or the opening provides a fatigue problem area.
Prior art nut retainers are disclosed by U.S. Pat. Nos. 2,078,411, granted Apr. 27, 1937 to Frederick G. Richardson, 2,421,201, granted May 27, 1947 to Robert L. Hallock, 2,986,188, granted May 30, 1961 to Joseph A. Karp and M. P. Haas, 3,126,039, granted Mar. 24, 1964 to Theodore E. Fiddler, 3,305,987, granted Feb. 28, 1967 to Floyd E. Weaver, 3,316,953, granted May 2, 1967 to Karl E. Fransson and Anders Larsson, 4,295,766, granted Oct. 20, 1981 to Francis Shaw, 4,768,907, granted Sep. 6, 1988 to Richard F. Gauron, 4,830,557, granted May 16, 1989 to David J. Harris and Richard L. Elgin, by British Patent No. 495,976, granted November 1938 to Swanstron, and by Swiss Patent No. 482,929, granted Dec. 15, 1969 to Josef Bucheli.